improve docs

check/dbip.go

@@ -26,7 +26,7 @@ func (d dbip) Json() ([]byte, error) {
 	return json.Marshal(d)
 }
 
-// DBip gets geolocation data from https://db-ip.com/db/download/ip-to-city-lite
+// DBip gets geolocation from https://db-ip.com/db/download/ip-to-city-lite.
 func DBip(ip net.IP) (checkip.Result, error) {
 	result := checkip.Result{
 		Name: "db-ip.com",

check/firehol.go

@@ -13,7 +13,7 @@ type firehol struct {
 	blacklisted bool
 }
 
-// Firehol checks whether the ipaddr is found on a blacklist from
+// Firehol checks whether the ipaddr is found on blacklist
 // https://iplists.firehol.org/?ipset=firehol_level1.
 func Firehol(ipaddr net.IP) (checkip.Result, error) {
 	result := checkip.Result{

check/ipsum.go

@@ -11,7 +11,8 @@ import (
 	"github.com/jreisinger/checkip"
 )
 
-// IPSum checks how many blacklists the ipaddr is found on.
+// IPSum checks how many blacklists the ipaddr is found on. It uses
+// https://raw.githubusercontent.com/stamparm/ipsum/master/ipsum.txt.
 func IPSum(ipaddr net.IP) (checkip.Result, error) {
 	result := checkip.Result{
 		Name: "github.com/stamparm/ipsum",

check/iptoasn.go

@@ -29,8 +29,8 @@ func (a AutonomousSystem) Json() ([]byte, error) {
 	return json.Marshal(a)
 }
 
-// IPtoASN gets info about autonomous system (IPtoASN) of the ipaddr. The data
-// is taken from a TSV file ip2asn-combined downloaded from iptoasn.com.
+// IPtoASN gets info about autonomous system of the ipaddr. The data is taken
+// from https://iptoasn.com/data/ip2asn-combined.tsv.gz.
 func IPtoASN(ipaddr net.IP) (checkip.Result, error) {
 	result := checkip.Result{
 		Name: "iptoasn.com",

check/otx.go

@@ -16,8 +16,8 @@ type otx struct {
 	} `json:"pulse_info"`
 }
 
-// OTX counts pulses on otx.alienvault.com to find out whether the ipaddr is
-// malicious.
+// OTX counts pulses to find out whether the ipaddr is malicious. Is uses
+// https://otx.alienvault.com/api/v1/indicators/IPv4.
 func OTX(ipaddr net.IP) (checkip.Result, error) {
 	result := checkip.Result{
 		Name: "otx.alienvault.com",

check/tls.go

@@ -36,8 +36,7 @@ func (t tlsinfo) Json() ([]byte, error) {
 	return json.Marshal(t)
 }
 
-// Tls finds out TLS version and SANs by connecting to the ipaddr and TCP port
-// 443.
+// Tls finds out TLS information by connecting to the ipaddr and TCP port 443.
 func Tls(ipaddr net.IP) (checkip.Result, error) {
 	result := checkip.Result{
 		Name: "cert",